Polycarbonate Resin Pellets and Light Guide Plate Produced Using the Same

Patent metadata

Field	Value
Publication number	US-2016185901-A1
Application number	US-201514972277-A
Country	US
Kind code	A1
Filing date	Dec 17, 2015
Priority date	Dec 31, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

Polycarbonate resin pellets are disclosed herein. The polycarbonate resin pellets are formed of a polycarbonate resin composition having a melt-flow index (MI) of about 15 g/10 min to about 40 g/10 min as measured at about 250° C. under a load of about 1.2 kgf in accordance with ASTM D1238, wherein the polycarbonate resin pellets have a ratio of an average major diameter to an average minor diameter (average major diameter:average minor diameter) of about 1:0.5 to about 1:1 and a bulk density of about 600 g/cm 3 to about 800 g/cm 3 . The polycarbonate resin pellets can reduce generation of powder chips caused by friction between pellets, thereby reducing appearance defects upon injection molding.

First claim

What is claimed is:

1 . Polycarbonate resin pellets formed of a polycarbonate resin composition having a melt-flow index (MI) of about 15 g/10 min to about 40 g/10 min as measured at about 250° C. under a load of about 1.2 kgf in accordance with ASTM D1238,
wherein the polycarbonate resin pellets have a ratio of an average major diameter to an average minor diameter (average major diameter:average minor diameter) of about 1:0.5 to about 1:1 and a bulk density of about 600 g/cm 3 to about 800 g/cm 3 .

2 . The polycarbonate resin pellets according to claim 1 , wherein the polycarbonate resin pellets are (elliptic) cylinder-shaped pellets having an average major diameter of about 2.0 mm to about 4.0 mm, an average minor diameter of about 1.5 mm to about 3.5 mm, and an average length of about 2.0 mm to about 4.0 mm.

3 . The polycarbonate resin pellets according to claim 1 , comprising: less than about 50 ppm of powder chips having passed through an about 600 μm filter, as measured after the polycarbonate resin pellets are subjected to tumbling at about 18 rpm for about 8 hours.

4 . The polycarbonate resin pellets according to claim 1 , wherein the polycarbonate resin composition comprises a polycarbonate resin which is a polymer of an aromatic dihydroxy compound and a diaryl carbonate, has a mole ratio of the aromatic dihydroxy compound to the diaryl carbonate of about 1:1.02 to about 1:1.35 and a weight average molecular weight of about 10,000 g/mol to about 18,000 g/mol, and comprises about 5 mol % to about 30 mol % of terminal hydroxyl groups based on a total amount of terminal groups.

5 . A light guide plate injection-molded from the polycarbonate resin pellets according to claim 1 .

6 . The light guide plate according to claim 5 , comprising: a front surface; a back surface facing the front surface; and a side surface connecting the front surface to the back surface, wherein the back surface comprises an optical pattern formed thereon.

7 . The light guide plate according to claim 5 , wherein the side surface comprises: a first side surface at which a light source is disposed; a second side surface facing the first side surface; a third side surface connecting the first side surface to the second side surface; and a fourth side surface facing the third side surface and connecting the first side surface to the second side surface.

8 . The light guide plate according to claim 5 , wherein the light guide plate has an appearance defect rate of about 15% or less, as caused by white spots and gases upon injection molding.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Chei Woo Suk
• Lee Jong Won
• Hur Jong Chan
• Jang Hyun Hye
• Chi Jun Ho

Classifications

• C08G64/06 Primary

  not containing aliphatic unsaturation · CPC title

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• B29B9/12

  characterised by structure or composition · CPC title

• B29B9/06

  in the form of filamentary material, e.g. combined with extrusion · CPC title

• C08L69/00 Primary

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title